The interference pattern is obtained with two coherent light sources of intensity ratio 4 : 1. And the ratio $${{{I_{\max }} + {I_{\min }}} \over {{I_{\max }} - {I_{\min }}}}$$ is $${5 \over x}$$. Then, the value of x will be equal to :

A light whose electric field vectors are completely removed by using a good polaroid, allowed to incident on the surface of the prism at Brewster's angle. Choose the most suitable option for the phenomenon related to the prism.

The two light beams having intensities I and 9I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $$\pi$$/2 at point P and $$\pi$$ at point Q. Then the difference between the resultant intensities at P and Q will be :

A light wave travelling linearly in a medium of dielectric constant 4, incidents on the horizontal interface separating medium with air. The angle of incidence for which the total intensity of incident wave will be reflected back into the same medium will be :

(Given : relative permeability of medium $$\mu$$_r = 1)